package net.pingsoft.kelefa.pool;
import java.sql.*;
import javax.sql.*;
import com.wish.JDBC.WConnection;
import org.apache.commons.pool.*;
import org.apache.commons.pool.impl.*;
/**
* 数据库链接的接口类.直接调用静态方法getDBConnection()取得Connection对象.
* 相关的参数由PoolConfigServlet类根据web.xml设置,所以web.xml需要注册PoolConfigServlet
*
* Copyright: Copyright (c) 2004
* @author kelefa yang
* @version 1.0
* @see PoolConfigServlet
*/
public class DatabaseConnection
{
/** 数据库的用户名 */
public static String USER = "sa";
/** 数据库的用密码 */
public static String PASS = "yf1";
/** 数据库的启动程序类名 */
public static String DBDRIVER =
"com.microsoft.jdbc.sqlserver.SQLServerDriver";
/** 数据库的链接地址 */
public static String DBURL =
"jdbc:microsoft:sqlserver://192.9.200.23:1433;DatabaseName=FC";
/** 是否使用jndi */
public static boolean useJNDI = false;
/** jndi的名字,useJNDI==false时无效 */
public static String JNDI = "wishJndi";
/**
* 是否对数据库链接进行编码转换
* @deprecated 没有进行测试,应该直接设置数据库或在链接url加上编码参数
*/
public static boolean convertConnetion = false;
/** 是否缓冲链接 */
public static boolean POOL_CONNECTION = false;
/**
* 没有必要生成实例
*/
private DatabaseConnection()
{}
/**
* 根据相应参数取回实际的数据库链接.
* 如果useJNDI为真,根据JNDI名字从数据源取链接;否则直接从jdbc取链接.
* 如果convertConnetion为真,对链接再封装,实现编码的转换.
* @throws Exception 当useJNDI==false,并且USER,PASS,DBDRIVER,DBURL其中一个为空时
* 抛出"DatabaseConnection didn't init!!"异常
* @return Connection 数据库链接,取不到时返回null
*/
static Connection getConnection() throws Exception
{
Connection conn = null;
if( !useJNDI )
{
if( ( USER == null ) || ( PASS == null ) || ( DBDRIVER == null ) ||
( DBURL == null ) )
throw new Exception( "DatabaseConnection didn't init!!" );
Class.forName( DBDRIVER );
conn = DriverManager.getConnection( DBURL, USER, PASS );
}
else
{
DataSource ds = ServiceLocator.getInstance().getDataSource( JNDI );
conn = ds.getConnection();
}
if( convertConnetion && conn != null )
return new WConnection( conn );
else
return conn;
}
/** 链接池工厂 */
private static GenericObjectPoolFactory poolFactory =
new GenericObjectPoolFactory( new ConnectionFactory() );
/** 数据库链接池 */
private static ObjectPool pool = poolFactory.createPool();
/**
* if POOL_CONNECTION is true, return the pooled connetion.
* POOL_CONNECTION will be set in Class PoolConfigServlet when webapp start,
* you can change the value in web.xml.
*
* <init-param> * <param-name>poolConnection</param-name> * <param-value>true</param-value> * </init-param> * * @throws Exception * @return Connection */ public static Connection getDBConnection() throws Exception { if( POOL_CONNECTION ) { Object obj = pool.borrowObject(); if( null == obj ) return null; PoolableConnection conn = ( PoolableConnection )obj; conn.setPool( pool ); return conn; } else return getConnection(); } } 2. 数据库链接工厂类ConnectionFactory
package net.pingsoft.kelefa.pool;
import org.apache.commons.pool.*;
import java.sql.Connection;
/**
* 数据库链接对象工厂，负责创建数据库链接对象，并把它封装成可缓冲的对象以及关闭数据库链接。
* 这个工厂实例作为org.apache.commons.pool.impl.GenericObjectPoolFactory的构造函数的
* 参数。
*
* Copyright: Copyright (c) 2004
* @author kelefa yang
* @version 1.0
* @see org.apache.commons.pool.impl.GenericObjectPoolFactory
*/
public class ConnectionFactory extends BasePoolableObjectFactory
{
public ConnectionFactory()
{
}
/**
* Creates a Connection instance that can be returned by the pool.
*
* @return an instance that can be returned by the pool.
* @throws Exception
* @todo Implement this org.apache.commons.pool.PoolableObjectFactory method
*/
public Object makeObject() throws Exception
{
Connection conn = DatabaseConnection.getConnection();
if (conn==null)
return null;
return new PoolableConnection(conn);
}
/**
* close a Connection instance no longer needed by the pool.
*
* @param obj the instance to be destroyed
* @throws Exception
* @todo Implement this org.apache.commons.pool.PoolableObjectFactory method
*/
public void destroyObject( Object obj ) throws Exception
{
PoolableConnection conn = (PoolableConnection)obj;
conn.setPool( null );
conn.close();
}
}
3. 重载Connection.close()方法,使得可以返回数据库链接池
package net.pingsoft.kelefa.pool;
import java.sql.Connection;
import java.sql.SQLException;
import org.apache.commons.pool.*;
/**
* 重载Connection.close()方法,使得可以返回数据库链接池.
*
* Copyright: Copyright (c) 2004
* @author kelefa yang
* @version 1.0
*/
public class PoolableConnection extends ConnectionWrap
{
/** 数据库链接池 */
private ObjectPool pool;
public PoolableConnection(Connection conn)
{
super(conn);
}
/**
* 如果数据库链接池存在,则将这个链接返回数据库链接池;否则关闭这个数据库链接
* @throws SQLException
*/
public void close() throws SQLException
{
try
{
if (pool != null)
pool.returnObject( this );
else
super.close();
}
catch( Exception ex )
{
}
}
/**
* 设置这个链接所在的链接池.
* 如果pool等于null,链接用完直接关闭,否则用完后返回链接池中.
* @param pool 数据库链接池
*/
public void setPool(ObjectPool pool)
{
this.pool = pool;
}
}
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